1. Field of the Invention
The present invention relates to a heading die. More particularly, the present invention relates to a hot-forging heading die used in metalworking to form a “head” on the end of a steel rod, such as in the manufacture of ejector pins.
2. Description of the Related Art
Heading dies have long been used in cold and hot forging metalworking processes to form an enlarged “head” on the end of a metal rod that will define an element of the finished part. For example, a number of components used in the construction of injection molds, such as ejector pins, core pins, return pins, valve pins, and sleeves, as well as many non-molding industry parts such as screws, bolts, rivets, etc., are typically configured to have an elongated body with a head at one end to limit travel, orient the component or provide a finished or partially formed end for further machining processes.
The typical construction of a heading die comprises a hardened steel ring with a cylindrical carbide insert. Pre-forming the internal configuration during the manufacture of the carbide insert and/or normal machining methods are used to create an axial bore completely through the insert, the rod or body of the part passing through this bore during the forging process. The heading cavity is created by machining a suitably sized counterbore (concentric with the axial through bore) that will ultimately form the head during the cold or hot forging process. The prior art heading dies used for this purpose have a cavity on only one side of the die. Accordingly, when the insert became chipped, otherwise damaged or worn beyond acceptable tolerances, the die became unusable, necessitating its complete replacement by a new die.